// 设置dialog拖动指令
// v-dialogDrag: 弹窗拖拽
import Vue from 'vue'
Vue.directive('dialogDrag', {
  bind(el, binding, vnode, oldVnode) {
    const dialogHeaderEl = el.querySelector('.el-dialog__header')
    const dragDom = el.querySelector('.el-dialog')
    dialogHeaderEl.style.cssText += ';cursor:move;'
    dragDom.style.cssText += ';top:0px;'

    // 获取原有属性 ie dom元素.currentStyle 火狐谷歌 window.getComputedStyle(dom元素, null);
    const sty = (() => {
      if (window.document.currentStyle) {
        return (dom, attr) => dom.currentStyle[attr]
      } else {
        return (dom, attr) => getComputedStyle(dom, false)[attr]
      }
    })()

    dialogHeaderEl.onmousedown = (e) => {
      // 鼠标按下，计算当前元素距离可视区的距离
      const disX = e.clientX - dialogHeaderEl.offsetLeft
      const disY = e.clientY - dialogHeaderEl.offsetTop

      const screenWidth = document.body.clientWidth // body当前宽度
      const screenHeight = document.documentElement.clientHeight // 可见区域高度(应为body高度，可某些环境下无法获取)

      const dragDomWidth = dragDom.offsetWidth // 对话框宽度
      const dragDomheight = dragDom.offsetHeight // 对话框高度

      const minDragDomLeft = dragDom.offsetLeft
      const maxDragDomLeft = screenWidth - dragDom.offsetLeft - dragDomWidth

      const minDragDomTop = dragDom.offsetTop
      const maxDragDomTop = screenHeight - dragDom.offsetTop - dragDomheight

      // 获取到的值带px 正则匹配替换
      let styL = sty(dragDom, 'left')
      let styT = sty(dragDom, 'top')

      // 注意在ie中 第一次获取到的值为组件自带50% 移动之后赋值为px
      if (styL.includes('%')) {
        styL = +document.body.clientWidth * (+styL.replace(/\%/g, '') / 100)
        styT = +document.body.clientHeight * (+styT.replace(/\%/g, '') / 100)
      } else {
        styL = +styL.replace(/\px/g, '')
        styT = +styT.replace(/\px/g, '')
      }

      document.onmousemove = function(e) {
        // 通过事件委托，计算移动的距离
        let left = e.clientX - disX
        let top = e.clientY - disY

        // 边界处理
        if (-(left) > minDragDomLeft) {
          left = -(minDragDomLeft)
        } else if (left > maxDragDomLeft) {
          left = maxDragDomLeft
        }

        if (-(top) > minDragDomTop) {
          top = -(minDragDomTop)
        } else if (top > maxDragDomTop) {
          top = maxDragDomTop
        }

        // 移动当前元素
        dragDom.style.cssText += `;left:${left + styL}px;top:${top + styT}px;`
      }

      document.onmouseup = function(e) {
        document.onmousemove = null
        document.onmouseup = null
      }
    }
  }
})

Vue.directive('enterSearch', {
  bind(el, binding) {
    el.addEventListener('keydown', (event) => {
      if (event.key === 'Enter') {
        event.preventDefault()
        if (binding.value) {
          binding.value()
        }
      }
    })
  }
})


// 处理el-select组件无下拉框选项时,无法显示问题
Vue.directive('NoDataShow', {
  bind(el, binding,vnode) {
	const newElement = document.createElement('p')
	newElement.innerHTML = '无数据'
	newElement.className = 'el-select-dropdown__empty'
    el.addEventListener('click', (event) => {
		let len=vnode.child.popperElm.childNodes[0].childNodes[0].childNodes[0].childNodes.length
		let elm=vnode.child.popperElm
		elRemove()
		if(len==0){
			if(elm.style.display=='none'){
				elAppende()
				elm.style.display='block'
			}else{
				elm.style.display='none'
			}
		}
    })
    el.querySelector('input').addEventListener('blur', (event) => {
	    let style=vnode.child.popperElm.style
	    let len=vnode.child.popperElm.childNodes[0].childNodes[0].childNodes[0].childNodes.length
		let elm=vnode.child.popperElm
		elRemove()
	    if(len==0&&style.display=='block'){
			elm.style.display='none'
			elRemove()
	    }
    })
	el.querySelector('input').addEventListener('input', (event) => {
		let elm=vnode.child.popperElm
		elRemove()
	  
	})
	function elRemove(){
		let elm=vnode.child.popperElm
		if(elm.contains(newElement)){
			elm.removeChild(newElement)
		}
	}
	function elAppende(){
		let elm=vnode.child.popperElm
		if(!elm.contains(newElement)){
			elm.appendChild(newElement)
		}
	}
  }
})